Hi @ruud.vantongeren,
Thank you for posting to the BIM 360 Docs Forum. The reason you are only seeing PDF and image files is because BIM 360 Docs Submittals is only designed to support these types. For more information, please see the Help documentation To Work with Submittals under Create Submittal Item.
If there is an improvement that you would like to see around the Submittals feature, I strongly encourage you to post to the BIM 360 Ideas site with your suggestion. If you are interested in seeing inclusion of Revit files, you can VOTE UP the existing Idea here.
If the information provided helps answer your forum post, please choose Accept as Solution so that other members can find the answer as well. Let us know if you have any questions.
Best regards,
Patrick B.
Global Product Support